It's certainly good to regularly monitor blood sugar levels, and the truth is that most diabetics don't really check themselves enough, and especially after meals. The medical community isn't helping much here and generally discourages after meal testing, because they just want you sticking to the diet they give you and the meds they give you and there's no input required at all from the patient.
So generally we don't worry near enough about our after meal blood sugar readings, or PP readings, which means post prandial, but on the other hand we don't want to go too far the other way either, and stress ourselves too much about readings that we may think are too high.
Blood sugar control really isn't that much about the acute management of the disease, people may feel a little unwell if their blood sugar goes up too much but this isn't the big deal here, what they are worried about, and rightly so, is the long term effects of too high blood sugar upon the body.
High blood sugar, unless it is high to extremes, doesn't do its damage acutely at all, in other words if you are running in the 300's it's not the fact that you are running there now that matters, it's running this high over a long period of time that does you in, and this is measured in years, not minutes or hours.
In the distribution of risk, there may be a little difference in looking at the peaks instead of the averages, but in the end it's the area under the curve so to speak that makes the difference one way or the other, which means that we're talking about the average amount that one is above normal.
So if your blood sugar average is 150 for instance, and you have a corresponding A1C of 6.9% we'll say, which is the average of the glycation (stickiness) of your red blood cells over time, this is the stuff that's correlated with risk of damage, and in particular, A1C readings are used here, since they more directly measure what high glucose does to us.
So in other words the high glucose is "damaging" our blood cells, and although glycated blood cells aren't dangerous, it gives us a pretty good idea, not a perfect one but a pretty good one, as far as what might be going on with glycation in other cells, and a better idea actually than just measuring blood sugar levels.
If one tends to go hypo, this is going to affect things though, and now we have areas under the curve, below the ideal, and this is going to skew the A1C results as well as the average blood sugar results, but provided that you don't go below normal, A1C and average blood sugar measurements are what we want to look at, not peaks.
Now looking at peaks can help us manage these elements though, for instance if you eat a meal that puts you up a lot and then substitute it with something else that spikes you less, well that can be good for blood sugar management overall.
Post prandial readings are relative to where one is before the meal though, and that certainly has to be taken into account, and if someone is already over whatever the PP goal is before the meal, it's not likely they are going to stay within the limits.
There is all sorts of debate as far as what after meal blood sugar goals should be, the ADA suggests 180, some suggest 140, some even 120, Dr. Bernstein wants us below 90 which is pretty crazy, and there's a doctor who in this article states that under 200 is fine and should be the goal.
People are making fun of this guy, those who subscribe to much lower targets, and I don't think that they are thinking this through that much though. He's recommending under 200 for after meals and under 126 pre meal, or fasting, and that's pretty reasonable actually and really out of line with what is being prescribed generally, by the ADA for instance, especially when it comes to A1C, and if someone is able to achieve this they should be able to achieve the ADA's goal of <7 A1C.
It was that 200 number that had people getting bent out of shape though, people who are already horrified with the 180 number that the ADA promotes, but I think that these people are too concerned with PP readings generally, and what really matters is the big picture, your averages or your A1C.
Of course what these should be is a matter of quite some debate as well, but let's at least get the debate focused on what really matters, blood sugar overall, and how much one spikes, or what one's PP readings are, which by the way isn't the same thing, as spikes are actually how much you go up from a meal.
So this stuff is only important to the degree that it contributes to overall blood sugar, and in fact with the ADA's goal of under 7 A1C, the 180 PP recommendations are actually pretty modest, and one could go over that typically and still meet their overall goals.
The upshot of all of this is that it takes the focus off of what's most important, overall blood sugar management, which is more than just looking at a particular type of reading that is pretty transitory and comprises a minority of our overall daily readings.